<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <div class="main">
        <div>测试文字</div>
    </div>
</body>
<style>
    .main{
        width: 500px;
        height: 500px;
        background: skyblue;
        display: flex;
        align-items: flex-start;
    }
    .main div{
        background: pink;
        flex: 1;
        /* flex-shrink: 1;
        flex-basis: 0%;
        flex-grow: 1; */
    }
</style>
</html>